On 12.02.20 12:21, Sergey Dyasli wrote: > Hi Juergen, > > Recently our testing has found a host crash which is reproducible. > Do you have any idea what might be going on here? Oh, nice catch! The problem is that get_cpu_idle_time() is calling vcpu_runstate_get() for an idle vcpu. This is fragile as idle vcpus are sometimes assigned temporarily to normal scheduling units, thus the ASSERT() in the unlock function is failing when the assignment of the idle vcpu is modified under the feet of vcpu_runstate_get() and the unit it has been assigned to before is already scheduled on another cpu. The patch is rather easy, though. Can you try it, please? Juergen